Bulletproof flux-cored wire and preparation method and application thereof

Abstract

The invention provides a bulletproof flux-cored wire as well as a preparation method and application thereof, and relates to the technical field of flux-cored wires. A flux core of the flux-cored wire comprises, by mass, 5%-9% of zinc, 0.8%-2% of ferrosilicon, 10%-15% of ferrochromium, 10%-16% of molybdenum, 3%-5% of high-carbon ferromanganese, 7%-17% of rutile, 1%-3% of ferroaluminum, 12%-17% of manganese, 0.2%-1% of copper, 3%-7% of sodium fluoride, 3%-5% of ferrotitanium and the balance iron. The bulletproof flux-cored wire solves the technical problem that a welding joint welded by a bulletproof welding wire in the prior art has obvious softening behavior and cannot resist short-distance shooting damage of rifle bullets, and achieves the effects that the flux-cored wire has enough strength and hardness to ensure the bulletproof performance of the welding joint, and meanwhile, the flux-cored wire has enough toughness to absorb impact energy, so that the service life of the bulletproof flux-cored wire is prolonged. The technical effects of relatively good corrosion resistance and high temperature resistance are also achieved.

Description

Technical Field

[0001] The invention relates to the technical field of flux-cored welding wires, and in particular to a bulletproof flux-cored welding wire and a preparation method and application thereof. Background Art

[0002] When manufacturing bulletproof transport vehicles, if a large number of riveted joints are used, it will not only increase the vehicle's weight and energy consumption, but also the vibration and noise of the riveted joints will affect the comfort of the vehicle. Using welding wire instead of riveted joints can not only reduce the vehicle's weight, but also improve the flatness of the vehicle surface, further improve the bulletproof performance, and at the same time reduce the vibration and noise generated during transportation.

[0003] However, the existing bulletproof welding wire adopts ordinary solid welding wire gas shielded welding, and the softening behavior of the welded joint is very obvious. The welded joint after welding cannot resist the damage of close-range shooting of rifle bullets. At the same time, the martensite and bainite of ordinary solid welding wire will decompose to varying degrees during the welding process, resulting in the reduction of the bulletproof performance of the welding heat affected zone.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] One of the purposes of the present invention is to provide a bulletproof flux-cored welding wire, which has sufficient strength and hardness to ensure the bulletproof performance of the welding joint, and has sufficient toughness to absorb impact energy and avoid cracking, and also has better corrosion resistance and high temperature resistance.

[0006] The second object of the present invention is to provide a method for preparing a bulletproof flux-cored welding wire, which has a simple process, high efficiency, high success rate and is suitable for industrial production.

[0007] The third object of the present invention is to provide an application of a bulletproof flux-cored welding wire, which is beneficial to improving the bulletproof performance of a bulletproof transport vehicle and has an outstanding application effect.

[0008] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0009] In a first aspect, a bulletproof flux-cored welding wire, the flux core of the flux-cored welding wire comprises the following components by mass percentage:

[0010] Zinc 5%-9%, ferrosilicon 0.8%-2%, ferrochrome 10%-15%, molybdenum 10%-16%, high carbon ferromanganese 3%-5%, rutile 7%-17%, ferroaluminum 1%-3%, manganese 12%-17%, copper 0.2%-1%, sodium fluoride 3%-7%, ferrotitanium 3%-5%, and the balance iron.

[0011] Furthermore, the ferrosilicon includes 45 ferrosilicon.

[0012] Furthermore, the manganese includes electrolytic manganese.

[0013] Furthermore, the titanium iron includes 70 titanium iron.

[0014] Furthermore, the particle size of the drug core is 80 meshes-100 meshes.

[0015] Further, the coating of the flux-cored welding wire comprises 304 stainless steel;

[0016] The flux core filling rate of the flux cored welding wire is 20%-30%.

[0017] Furthermore, the diameter of the flux-cored welding wire is 1.2 mm-1.6 mm.

[0018] In a second aspect, a method for preparing the flux-cored welding wire according to any one of the above items comprises the following steps:

[0019] (a) mixing the components in proportion to obtain a drug core;

[0020] (b) adding the flux core into the steel strip groove and then sealing it to obtain the flux cored welding wire.

[0021] Furthermore, after the sealing, a step of wire drawing and reducing the diameter is also included.

[0022] A third aspect is the use of a flux-cored welding wire as described in any of the above items in the manufacture of bulletproof transport vehicles.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects:

[0024] The bulletproof flux-cored welding wire provided by the present invention, under the coordinated cooperation of various components and their specific proportions, not only has sufficient strength and hardness to ensure the bulletproof performance of the welded joint, the tensile strength of the weld metal of the flux-cored welding wire is between 600Mpa and 900Mpa, which can resist the damage caused by close-range shooting of rifle bullets, and at the same time has sufficient toughness to absorb impact energy and avoid cracking, and also improves the corrosion resistance and high temperature resistance by adding specific alloy elements.

[0025] The method for preparing the bulletproof flux-cored welding wire provided by the invention has simple process, high efficiency, high success rate and is suitable for industrial production.

[0026] The application of the bulletproof flux-cored welding wire provided by the present invention is beneficial to improving the bulletproof performance of a bulletproof transport vehicle, and the application effect is outstanding. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A flow chart for preparing a bulletproof flux-cored welding wire provided in accordance with one embodiment of the present invention. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] According to a first aspect of the present invention, there is provided a bulletproof flux-cored welding wire, the flux core of the flux-cored welding wire comprising the following components by mass percentage:

[0031] Zinc 5%-9%, ferrosilicon 0.8%-2%, ferrochrome 10%-15%, molybdenum 10%-16%, high carbon ferromanganese 3%-5%, rutile 7%-17%, ferroaluminum 1%-3%, manganese 12%-17%, copper 0.2%-1%, sodium fluoride 3%-7%, ferrotitanium 3%-5%, and the balance iron.

[0032] In the present invention, the typical but non-limiting mass percentage of zinc is, for example, 5%, 6%, 7%, 8%, 9%; the typical but non-limiting mass percentage of ferrosilicon is, for example, 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%; the typical but non-limiting mass percentage of ferrochromium is, for example, 10%, 11%, 12%, 13%, 14%, 15%; the typical but non-limiting mass percentage of molybdenum is, for example, 10%, 11%, 12%, 13%, 14%, 15%, 16%; the typical but non-limiting mass percentage of high carbon ferromanganese is, for example, 3%, 4%, 5%; the typical but non-limiting mass percentage of rutile ...10%, 11%, 12%, 13%, 14%, 15%, 16%; the typical but non-limiting mass percentage of high carbon ferromanganese is, for example, 10%, 11%, 12%, Typical but non-limiting mass percentages of ferroaluminum are, for example, 1%, 2%, 3%; typical but non-limiting mass percentages of manganese are, for example, 12%, 13%, 14%, 15%, 16%, 17%; typical but non-limiting mass percentages of copper are, for example, 0.2%, 0.4%, 0.6%, 0.8%, 1%; typical but non-limiting mass percentages of sodium fluoride are, for example, 3%, 4%, 5%, 6%, 7%; typical but non-limiting mass percentages of ferrotitanium are, for example, 3%, 4%, 5%.

[0033] The bulletproof flux-cored welding wire provided by the present invention, under the coordinated cooperation of various components and their specific proportions, not only has sufficient strength and hardness to ensure the bulletproof performance of the welded joint, the tensile strength of the weld metal of the flux-cored welding wire is between 600Mpa and 900Mpa, which can resist the damage caused by close-range shooting of rifle bullets, and at the same time has sufficient toughness to absorb impact energy and avoid cracking, and also improves the corrosion resistance and high temperature resistance by adding specific alloy elements.

[0034] In the present invention, the corrosion resistance and high temperature resistance of the flux-cored welding wire are improved by adding specific alloying elements, such as molybdenum. Molybdenum is an effective alloying element that can not only improve the corrosion resistance of the weld metal, especially in a chlorine-containing environment, but also increase the metal strength, improve weldability, increase hardness and improve crack resistance. In short, the addition of molybdenum can greatly enhance the anti-ballistic performance of the flux-cored welding wire.

[0035] In a preferred embodiment, ferrosilicon includes but is not limited to 45 ferrosilicon, manganese includes but is not limited to electrolytic manganese, and ferrotitanium includes but is not limited to 70 ferrotitanium, which is more conducive to further improving the mechanical properties of the flux-cored welding wire, ensuring the quality and performance of the welded joint, and is more conducive to improving the anti-ballistic performance.

[0036] It should be noted that the specific ratio of the flux core components in the flux cored welding wire is extremely important and is the key to achieving the technical effect of the present invention. Each component needs to be accurately weighed and fully dried in proportion; the ratio of the flux core components will directly affect the slag formation, arc stability and chemical composition of the weld metal during welding; if the ratio of the flux core components is not within the scope of the present invention, it will not only lead to weld quality problems, such as easy occurrence of pores, cracks and inclusions, but also cause the mechanical properties (such as strength, toughness and hardness) and corrosion resistance of the weld to fail to meet specific technical requirements, affecting the safety and service life of the welded structure; in short, the precise ratio of the flux core components is crucial to ensuring the welding performance and quality of the flux cored welding wire.

[0037] In a preferred embodiment, the particle size of the flux core can be 80 mesh-100 mesh, and its typical but non-limiting particle size is, for example, 80 mesh, 85 mesh, 90 mesh, 95 mesh, and 100 mesh. The appropriate particle size of the flux core is more conducive to further improving the welding performance and the anti-ballistic performance.

[0038] It should be noted that if the particle size of the drug core is too small, the following problems will occur:

[0039] 1. Increased production difficulty: During the production process of flux-cored welding wire, the fluidity of the powder decreases, which easily causes problems such as uneven distribution of the powder, thus affecting the quality and welding performance of the welding wire;

[0040] 2. The smaller the powder particle size, the better the thermal conductivity. However, the higher temperature inside the molten droplet may cause the arc stability to deteriorate, because the molten droplet transition may cause explosion and splashing, resulting in drastic changes in current and voltage, causing the arc stability to decrease.

[0041] It should be noted that if the particle size of the drug core is too large, the following problems will occur:

[0042] 1. The arc stability becomes worse: the larger the powder particle size, the worse the thermal conductivity, resulting in drastic changes in current and voltage, thus reducing the arc stability;

[0043] 2. Filling stability problem: Too large a powder particle size will affect the fluidity of the powder, thereby affecting the filling stability of the flux-cored welding wire; poor fluidity will lead to uneven distribution of the powder, causing looseness or powder breakage inside the welding wire, which is not conducive to stable welding and ensuring welding quality.

[0044] In a preferred embodiment, the coating of the flux-cored welding wire includes but is not limited to 304 stainless steel.

[0045] In the present invention, the flux core filling rate of the flux cored welding wire may be 20%-30%, and typical but non-limiting filling rates thereof are, for example, 20%, 22%, 24%, 26%, 28%, and 30%.

[0046] In a preferred embodiment, the diameter of the flux-cored welding wire may be 1.2 mm-1.6 mm, and typical but non-limiting diameters thereof are, for example, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, and 1.6 mm.

[0047] According to a second aspect of the present invention, there is provided a method for preparing the flux-cored welding wire as described in any one of the above, comprising the following steps:

[0048] (a) mixing the components in proportion to obtain a drug core;

[0049] (b) adding the flux core into the steel strip groove and then sealing it to obtain the flux cored welding wire.

[0050] The method for preparing the bulletproof flux-cored welding wire provided by the invention has simple process, high efficiency, high success rate and is suitable for industrial production.

[0051] In a preferred embodiment, the step of wire drawing and reducing the diameter is further included after sealing.

[0052] A typical preparation method of flux-cored welding wire, see Figure 1 , including the following steps:

[0053] (1) mixing the components in powder form according to proportion, drying and sieving to obtain drug core powder;

[0054] (2) When the steel belt gradually closes from U-shape to O-shape, a powder feeder is used to add the core powder into the steel belt groove;

[0055] (3) After the steel strip is formed, it is immediately transferred to the wire drawing machine for wire drawing and diameter reduction. After multiple wire drawing, it reaches the target specification and is collected by the wire collecting machine to obtain the finished flux-cored welding wire.

[0056] According to a third aspect of the present invention, there is provided a use of the flux-cored welding wire described in any one of the above items in the manufacture of bulletproof transport vehicles.

[0057] The application of the bulletproof flux-cored welding wire provided by the present invention is beneficial to improving the bulletproof performance of a bulletproof transport vehicle, and the application effect is outstanding.

[0058] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0059] Examples 1-6

[0060] Embodiment 1-6 provides a bulletproof flux-cored welding wire, which is composed of a flux coating and a flux core;

[0061] The coating is 304 stainless steel strip; the components in the core and their mass percentages are shown in Table 1.

[0062] Table 1

[0063]

[0064] Example 7

[0065] This embodiment is a method for preparing the bulletproof flux-cored welding wire of Embodiments 1-6, which sequentially includes the steps of raw material inspection, powder preparation, powder mixing, drying, screening, steel strip slitting and rewinding, powder adding, steel strip forming, wire drawing and reducing, and cleaning and storage;

[0066] The details are as follows:

[0067] S1 Raw material inspection:

[0068] 304 stainless steel strip inspection: The surface of the steel strip should be bright, smooth, without cracks, holes, oxide scale and corrosion holes;

[0069] Drug powder testing: The particle size of drug powder is 80-100 mesh;

[0070] S2 powder preparation:

[0071] The components of zinc powder, 45 ferrosilicon, ferrochrome, molybdenum powder, high carbon ferromanganese, rutile, ferroaluminum, electrolytic manganese, copper powder, sodium fluoride, 70 ferrotitanium and iron powder are added and mixed in the form of powder, and the particle size is between 80-100 mesh;

[0072] S3 powder mixing, drying and sieving:

[0073] The components of the powder are poured into a powder mixing furnace in proportion for mixing, the powder mixing furnace is heated to 120°C and dried for 2 hours, and then taken out and filtered with an 80-100 mesh screen to remove larger particles to obtain the flux core powder used in the preparation of welding wire;

[0074] S4 steel strip slitting and rewinding:

[0075] Cut the qualified 304 stainless steel strip into 10mm width and 0.4mm thickness according to the process requirements, and use the take-up machine to rewind the slit steel strip onto the I-shaped wheel for standby use;

[0076] S5 powder adding and steel strip forming:

[0077] The welding wire is made by 304 stainless steel strip forming method. The forming unit is composed of 7 pairs of upper and lower rollers in sequence. The steel strip is pulled into the forming unit for rolling. Between the third and fourth pairs of rollers of the forming machine, when the steel strip gradually closes from U-shape to O-shape, the powder feeder adds the pre-prepared flux core powder into the steel strip groove. Then the steel strip is sealed under the rolling pressure of the next set of rollers. The diameter of the obtained primary welding wire is 2.9mm-3.1mm, and the flux core filling rate of the welding wire is 20%-30%;

[0078] S6 wire drawing reduction:

[0079] After the steel strip is formed, it is immediately transferred to the wire drawing machine and enters the wire drawing and diameter reduction stage. After multiple wire drawing, the welding wire reaches the target size of 1.2mm-1.6mm, and then it is collected by the wire collecting machine to obtain flux-cored welding wire;

[0080] S7 Clean and Save:

[0081] After the welding wire is processed, first clean and remove the wire drawing powder remaining on the surface of the welding wire during the wire drawing process, and then store it in a dry environment until it is used for welding.

[0082] Comparative Example 1

[0083] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the flux core composition of this comparative example does not contain zinc, but is supplemented with an equal amount of iron;

[0084] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0085] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that the absence of zinc element will reduce the toughness and plasticity of the weld metal and affect the mechanical properties of the weld joint; the weld without zinc is more susceptible to corrosion by corrosive media, shortening the service life of the structure.

[0086] Comparative Example 2

[0087] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the mass percentage of zinc in the flux core composition of this comparative example is 4%;

[0088] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0089] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that the insufficient zinc content will reduce the toughness and plasticity of the weld metal and affect the mechanical properties of the weld joint.

[0090] Comparative Example 3

[0091] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the mass percentage of zinc in the flux core composition of this comparative example is 10%;

[0092] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0093] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that excessive zinc will be oxidized and evaporated under the action of arc heat, which can easily cause pores in the weld; the more zinc content, the more serious the evaporation and the greater the pore sensitivity.

[0094] Comparative Example 4

[0095] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the flux core composition of this comparative example does not contain molybdenum, but is supplemented with an equal amount of iron;

[0096] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0097] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that the welding wire without molybdenum will lead to insufficient strength of the weld metal; at the same time, the welding wire without molybdenum will lead to a different microstructure, which will affect the corrosion resistance and heat resistance of the weld.

[0098] Comparative Example 5

[0099] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the mass percentage of molybdenum in the flux core composition of this comparative example is 9%;

[0100] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0101] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that when the molybdenum content is low, the strength of the weld metal may be insufficient, causing the weld joint to be easily deformed or damaged when bearing load; at the same time, when the molybdenum content is low, the carbide content in the weld metal may be insufficient, thereby reducing its wear resistance.

[0102] Comparative Example 6

[0103] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the mass percentage of molybdenum in the flux core composition of this comparative example is 17%;

[0104] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0105] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that too high a molybdenum content will lead to the formation of intermetallic compounds, such as Laves phases, in the weld metal. These phases may precipitate during the welding process, causing embrittlement of the weld metal and increasing the tendency to crack. At the same time, in an oxidizing medium, the molybdenum element may promote the precipitation of Laves phases, which is not conducive to improving the pitting corrosion resistance of the weld metal.

[0106] Comparative Example 7

[0107] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the flux core composition of this comparative example does not contain sodium fluoride, but is supplemented with an equal amount of iron;

[0108] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0109] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that the flux-cored welding wire without sodium fluoride will increase spatter and smoke during welding, and the arc stability and process performance will be affected, resulting in a decrease in welding quality.

[0110] Comparative Example 8

[0111] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the mass percentage of ferrotitanium in the flux core composition of this comparative example is 2%;

[0112] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0113] Compared with Example 6, the defects of the flux-cored welding wire in this comparative example are that too low titanium content may lead to insufficient deoxidation, affecting the purity and performance of the weld metal; titanium can promote the formation of acicular ferrite, thereby affecting the microstructure of the deposited metal; low titanium content will lead to reduced formation of acicular ferrite in the deposited metal, thereby affecting the toughness and strength of the weld metal.

[0114] Comparative Example 9

[0115] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the mass percentage of ferrotitanium in the flux core composition of this comparative example is 6%;

[0116] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0117] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that excessive ferrotitanium content may affect the toughness of the deposited metal; solid-solution titanium can improve the strength and hardness of the structure, but excessive solid-solution titanium will deteriorate the toughness of the structure.

[0118] Test example

[0119] The performance of the flux-cored welding wires obtained in the embodiments and comparative examples was tested, and the results are shown in Table 2.

[0120] Table 2

[0121]

[0122] It can be seen from Table 2 that the flux-cored welding wire provided in Examples 1-6 of the present invention, under the coordinated cooperation of various components and their specific proportions, has sufficient strength and hardness to ensure the bulletproof performance of the welded joint, can resist the damage caused by close-range shooting of rifle bullets, and also has sufficient toughness to absorb impact energy and avoid cracks, and also has better corrosion resistance and high temperature resistance.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bulletproof flux-cored welding wire, characterized in that: The flux core of the flux cored welding wire comprises the following components by mass percentage: Zinc 5%-9%, ferrosilicon 0.8%-2%, ferrochrome 10%-15%, molybdenum 10%-16%, high carbon ferromanganese 3%-5%, rutile 7%-17%, ferroaluminum 1%-3%, manganese 12%-17%, copper 0.2%-1%, sodium fluoride 3%-7%, ferrotitanium 3%-5%, and the balance iron.

2. The flux-cored welding wire according to claim 1, characterized in that: The ferrosilicon includes 45 ferrosilicon.

3. The flux-cored welding wire according to claim 1, characterized in that: The manganese includes electrolytic manganese.

4. The flux-cored welding wire according to claim 1, characterized in that: The titanium iron includes 70 titanium iron.

5. The flux-cored welding wire according to any one of claims 1 to 4, characterized in that: The particle size of the drug core is 80-100 meshes.

6. The flux-cored welding wire according to any one of claims 1 to 4, characterized in that: The coating of the flux-cored welding wire comprises 304 stainless steel; The flux core filling rate of the flux cored welding wire is 20%-30%.

7. The flux-cored welding wire according to claim 6, characterized in that: The diameter of the flux-cored welding wire is 1.2 mm-1.6 mm.

8. A method for preparing a flux-cored welding wire according to any one of claims 1 to 7, characterized in that: The following steps are involved: (a) mixing the components in proportion to obtain a drug core; (b) adding the flux core into the steel strip groove and then sealing it to obtain the flux cored welding wire.

9. The preparation method according to claim 8, characterized in that: The step of wire drawing and reducing diameter is also included after the sealing.

10. Use of the flux-cored welding wire according to any one of claims 1 to 7 in the manufacture of bulletproof transport vehicles.

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